Strain-modulated electrical and optical bandgaps of tetragonal WO3: An HSE06 hybrid functional calculation
Feng Zhu,
Chun-Lan Ma,
Bei Gao,
Jia-Jing Kuai,
Jia-Yong Zhang,
Xiao-Hua Zhang
Affiliations
Feng Zhu
Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou 215009, China
Chun-Lan Ma
Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou 215009, China
Bei Gao
Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou 215009, China
Jia-Jing Kuai
Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou 215009, China
Jia-Yong Zhang
Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou 215009, China
Xiao-Hua Zhang
Innovation Center for Textile Science and Technology, Donghua University, Shanghai 201620, China
The Heyd–Scuseria–Ernzerhof screened hybrid functional is used to investigate the strain-modulated band structure and optical properties of tetragonal WO3. An electronic bandgap of 1.53 eV for the ground state of unstrained WO3 is obtained, which is consistent with the experimental value. Upon in-plane strains of 1.36%, 3.18%, 3.37%, and 4.36% along the directions of lattice vectors a→ and b→, i.e., biaxial strains, as realized by growing WO3 on the (001) surface of LaAlO3, NdGaO3, La0.3Sr0.7Al0.65Ta0.35O3, and SrTiO3, the bandgap decreases down to 1.47 eV, 1.37 eV, 1.36 eV, and 1.30 eV, respectively. The largest change in band structure can induce the downshift of the optical absorption edge, with the optical bandgap decreasing from 2.65 eV to 2.28 eV. Further applying a strain along the direction of lattice vector c→, the bandgap can be additionally tuned very finely. Our research provides a promising tuning method for designing high efficient inorganic photovoltaic materials.
